1. Field of the Invention
The invention relates to an annular disk for flexible shaft couplings, whose two coupling halves each exhibiting a connection flange are connected to each other via a packet of such annular disks in a torsionally rigid manner, but in such a way as to enable their axial and angular movement, wherein the disk packet is alternatingly secured to both connection flanges via circumferentially distributed attachment and clamping means, and wherein the annular disk has four attachment holes uniformly distributed on a shared hole circle, and the width of the annular disk section tapers between two consecutive attachment holes. The invention also relates to a disk packet made out of such annular disks, and a flexible shaft coupling with such annular disks.
2. Description of the Related Art
Couplings of this kind are known in the art, and have proven themselves in practice. They make it possible to offset both an axial and angular displacement of the shafts to be connected to each other. In addition, a radial displacement can also be offset if two such couplings are connected in series with the use of a so-called intermediate sleeve.
The object of the invention is to provide an annular disk of the kind mentioned at the outset that enables a higher axial displacement offset and higher angular displacement offset than conventional annular disks of this type while still having a high breaking strength. In particular, the object of the invention is to provide a disk packet or flexible shaft coupling for correspondingly large dislocations.
This object is essentially achieved according to the invention by having the annular disk satisfy the following geometric size rations:
Dt/D1=10 to 12, 
D2/Dt=1.1 to 1.2, 
Dt/B1=9 to 16, and 
B2/Dt=0.88 to 0.93, 
wherein Dt is the diameter of the hole circle, D1 is the diameter of the respective attachment hole, D2 is the largest outside diameter of the annular disk, B1 is the width of the narrowest part of the annular disk section between two consecutive attachment holes, and B2 is the width of the annular disk outer contour.
Tests have shown that shaft couplings with annular disks according to the invention can offset higher dislocations than conventional shaft couplings of this type at the same operational reliability.
Outstanding results were here achieved when the ratio of the hole circle diameter Dt to the smallest internal diameter D3 of the annular disk according to the invention ranged between 1.5 and 1.65.
It is also advantageous for the thickness of the individual annular disks to range between 0.2 and 0.4 mm. Chromium-nickel-steel, in particular X12CrNi 17 7, is preferred as the material for the annular disks.
Another advantageous embodiment of the invention relates to a disk packet comprised of annular disks according to the invention, in which plain washers with fretting corrosion-reducing surfaces are arranged between the individual annular disks or between packets comprised of several annular disks. This additionally improves the operational reliability of a correspondingly constructed shaft coupling. In another preferred embodiment, the plain washers can consist in particular of plastic, or have a sliding coating. Teflon(copyright) can preferably be used as the plastic or sliding coating.
Additional preferred and advantageous embodiments of the invention are described in the subclaims.